Multi-layer plastic articles are often used as containers to hold, food, beverages, pharmaceuticals, and nutraceuticals. Some multi-layer plastic articles are commonly made from materials such as polyethylene (PET) and polypropylene (PP). Articles made from PET and PP resist environmental degradation, and are reasonably durable, watertight, and economically produced. However, plastic materials such as PET and PP are gas (e.g., oxygen, nitrogen, etc.) permeable. For applications in which gas permeability is undesirable, for example, containers for food products, medicines and products that degrade upon gas permeation into or out of the container, a plastic article of PET or PP may include an interior layer of a barrier material or a gas scavenger material, such as ethylene vinyl alcohol (EVOH), between skin layers of PET or PP.
Molded plastic articles, such as containers for food, beverages, pharmaceuticals, nutraceuticals, etc., often have an open end used to fill the container with product. Some plastic containers also have an aperture, away from the open end. For example, some cartridges for single serve coffee machines have a multi-layer plastic body including an open top portion through which the container is filled with ground coffee and a smaller aperture in a bottom portion through which brewed coffee is dispensed. Such plastic bodies for single serve coffee machines are commonly made by first thermoforming the plastic body with a wide top portion, aligning the thermoformed article with a mechanical punch, and mechanically punching out the smaller aperture in a bottom portion. The additional separate cutting or punching step increases the complexity of the production process. Further, in applications where the accuracy or precision of the position of the aperture, or of the diameter of the aperture is important, sufficient accuracy or precision may be difficult to achieve with a punch process or a cutting process.
Other plastic containers including an open end portion and an aperture formed in a different portion of the container may commonly be formed or molded in separate pieces that are then joined together. For example, a plastic container for tooth paste (e.g., a tooth paste tube), may have a thin-walled tail end portion that is initially open to be filled with tooth paste before being sealed, and a thick-walled head end portion with a small aperture for dispensing the tooth paste. Such a container is commonly made by forming the thin-walled tail end portion, separately forming the thick-walled head end portion, and then joining the two pieces together.